Electric relay



March 15, 1966 HALFF ETAL 3,240,900

ELECTRIC RELAY Filed Dec. 21. 1961 2 sheets-sheet 1 INVENTORS ALBQT HALFF BY ALLEN f. 4 /0 March 15, 1966 HALFF ETAL 3,240,900

ELECTRIC RELAY Filed Dec. 21, 1961 2 Sheets-Sheet 2 INVENTORS Acaeqr HALFF BY ALLE E 4 5/0 ATTDQIYEY United States Patent 3,240,900 ELECTRIC RELAY Albert H. Halff, 4591 Rheims Place, and Allen F. Reid, 3145 Spur Trail, both of Dallas, Tex. Filed Dec. 21, 1961, Ser. No. 161,102 Claims. (Cl. 200-112) This invention relates to mercury type electrical relays and is directed particularly to electromagnetic actuated mercury relays that will operate in any position.

An object of this invention is to provide a mercury relay which is actuated by an electromagnetic coil and will operate in any position.

Other and further objects may be apparent from the following description taken in connection with the draw ings in which FIGURE 1 illustrates a side view of the relay with the electrodes in the horizontal position;

FIGURE 2 is a cross sectional view of the relay through the center of the sphere and with the electrodes in the vertical position;

FIGURE 3 is a side view of the relay with the electrodes at an angle to the horizontal;

FIGURE 4 is a perspective view of one of the plungers;

FIGURE 5 is an end view of the electrode and a sectional view of the plunger;

FIGURE 6 is a fragmentary view of another embodiment of the electrodes and plunger;

FIGURE 7 is another embodiment of the invention in which the electrodes are side by side; and

FIGURE 8 illustrates another embodiment of the invention in which a single electrode is at the center of the sphere and the other electrode is formed by conductive spherical surface supporting the mercury pool.

Referring to FIGURE 1, a side view of the relay is illustrated with the sphere fragmentized and the plunger shown in section. The enclosing sphere 10 is hollow and comprises an insulating or insulated wall for containing a mercury pool 11. The inner surface 12 of the sphere is also preferably spherical so that the surface 14 of the mercury pool will be a distance A from the center 15 of the inner surface 12 in any position of the relay. The distance A may vary slgihtly between the vertical and horizontal position due to the presence and/or absence of either electrode in the mercury pool. This variation is immaterial and is compensated for in the operation of the plunger 36. The sphere may be supported in any suitable manner, such as by cylindrical walls 18 The cylindrical walls 18 may be held against the sphere by fastening means, such as flanges 19 and bolts 20. The sphere may be manufactured in two halves which are held together by the Walls 18 and the fastening means with a suitable sealing means between the engaging edges of the two halves.

The wall of the sphere has holes 21 with bosses 22. The electrode supports 16 and 17 extend through the openings and are threaded in a respective boss to seal the respective openings. The electrode supports 16 and 17 are cylindrical insulator members, each having a respective longitudinally extending electrode 23, 24. The ends 23a, 24a of the electrodes extend from the inner ends of the supports and are spaced from one another and spaced a distance B from the center 15 of the sphere in a center area. In the horizontal position the mercury pool must rise the distance A in order to electrically connect the two electrodes.

In the vertical position the mercury pool must rise a distance A plus B in order to electrically connect the two electrodes. The electrodes 23 and 24 extend longitudinally through the electrode supports 16 and 17 and have exerior terminals 23b, 24b, to which leads 27 and 28 are "ice attached for connecting the electrodes to an electrical circuit 29. On immersion of the electrode ends 23a and 24a, the electrodes 23 and 24 are electrically connected and the circuit completed.

In this embodiment the electromagnetic coil 30 is mounted on the ring-shaped block 31 positioned outside of the sphere. A control current source 33 connected to the leads 34, 35 provides a current to create an electrical field or flux in the sphere to actuate the plunger 36 floating on the mercury pool 11. The coil 30 is preferably symmetrically positioned on opposite sides of the plane C extending through the center 15 of the sphere. The plane C is normal to the axis of the electrodes 23 and 24 so that the coil is normal to the electrodes. The flux of the coil is symmetrical about the plane C and converges at the center 15 of the sphere.

The plunger 36 is positioned inside of the sphere and floats on the mercury pool 11. The plunger may be cylindrical in shape and has a bore 37 extending through the plunger, The bore 37 may also be cylindrical and has a diameter greater than the diameter of the electrode supports 16 and 17 to permit lateral actuation of the plunger. As illustrated, the plunger 36 is positioned around the supports 16 and 17 to retain the sphere in the vicinity of the center 15. The diameter of the plunger is preferably greater than the length of the plunger in order to provide the necessary displacement. The plunger is made of magnetic material and may have some nonmagnetic material included for securing the desired density. The plunger floats on the mercury pool so as to be off-center from the center 15 and the center of the flux. On passage of current by coil 30 the flux draws the plunger downward, displacing the mercury and causing the level 14 to rise and immerse the ends of the electrodes. In FIGURE 1 the plunger is horizontal with the center of the plunger above the center 15 and thus off-center to the coil 30. On energization the plunger will center in the sphere by downward or axial lateral movement to immerse the electrodes. In FIGURE 2 the plunger 36 is vertical and moves axially downward to raise the level of the mercury of the pool. In FIGURE 3 the electrodes are at an angle to the surface of the mercury pool and the plunger 36 is off-center. On energization the plunger moves downward at an angle to the electrodes.

In order to protect the ends of the electrodes, projections 25 are provided around the electrodes to recess the ends (FIGURE 5). Spaces 26 are provided to permit the free flow of mercury to and from the ends of the elec trodes.

In FIGURE 6 an enlarged view of the electrodes and plunger is illustrated. The ends 23a and 24a of the electrode are located in a center area. The plunger 38 has an outer spherical surface 39 and a bore 40. The bore 40 is spaced from the electrode supports 16 and 17 to permit lateral movement of the plunger in response to the flux and immerse the plunger sufliciently to raise the level of the pool of mercury.

In FIGURE 7 the electrodes 41 and 42 extend through the same electrode support 43 to position the ends of the electrodes side by side, adjacent to the center 15 of the sphere For rigidity of support and to restrict the movement of the plunger, the support 43 extends diametrically across the sphere. Openings 44 are provided to permit the mercury to flow around the electrodes. The plunger 45 is similar to the plunger 36.

In FIGURE 8 another embodiment is illustrated in which the sphere 46 has a conductive metallic lining 47 with a terminal 48 extending through the sphere to electrically connect the sphere to an external circuit. The lining 47 covers the inner surface of the sphere so that the pool of mercury 49 is always in electrical contact therewith. The pool of mercury 49 is similar to the pool of mercury 11. Instead of two electrodes a single electrode 50 extends through the electrode support 51 to an outside terminal 52. The inner end of the electrode 50 is located at the center 15 for immersion in the pool on actuation of the plunger 53 by the coil 54.

It is thus seen from the foregoing description that an actuatable member such as the plunger 36 is floated offcenter in a spherically supported mercury pool and actuated by a field having a center corresponding to the center of the sphere to vary the level of the mercury pool a given amount irrespective of the position of the sphere or plunger. In the described embodiment the density of the plunger causes the plunger to float with the center above the center of the sphere. However, the plunger may have a higher density with the center below the center of the sphere and the electrodes normally immersed in the mercury pool. Thus this would form a relay having a normally closed circuit. The fiux would then raise the plunger, thereby lowering the level of the pool and opening the circuit. Thus the invention may be readily adapted to a normally open or a normally closed type of relay.

We claim:

1. An electric relay comprising a pool of liquid mercury, means for supporting said pool with a surface in substantially constant relation with a given center area irrespective of the position of the relay, conductive means in said center area for bridging by said mercury pool to pass current therewith, an electromagnetic coil forming a flux having the center convergence in said center area and a magnetic plunger floating in said mercury pool in an offset position on deenergization of said coil irrespective of the position of said relay and actuated by the coil to move to an intermediate position varying the surface of the pool with respect to said conductive means.

2. An electric relay comprising a hollow means having an inner spherical surface for containing mercury, a pool of mercury in the hollow member with the surface of the pool a given distance from the center of the spherical surface, in any position of said relay two electrodes extending within said spherical surface with their ends adjacent to the center of said surface and spaced a short distance apart, a plunger extending around said electrodes and freely floating in said mercury pool, in any position of said relay an electromagnetic coil positioned around said plunger to move said plunger toward the center of said spherical surface to vary the level of said mercury pool and alter the electrical relationship of the spaced electrodes,

3. An electric relay comprising a hollow means having an inner spherical surface defining an inner chamber, an electromagnetic coil forming a flux converging at the center of said spherical surface, a mercury pool supported by said surface to form a surface on said pool forming a clear center space at one given level, a lunger having a bore floating in said pool off-center to the center of said sphere to position the mercury surface at the one given level and to position the mercury surface in the center space on centering of the plunger by the flux of the coil, electrodes extending from said hollow means into the center space of said inner chamber and spaced from one another, said electrodes extending into the bore of said plunger for positioning the plunger around the electrodes to vary the electrical conductivity by said mercury on actuation of said plunger from an offset position irrespective of the position of said electrodes.

4. An electric relay comprising a spherical member having an inner spherical surface forming an inner chamher, a mercury pool in said chamber resting on the spherical surface to form a surface on said pool spaced a given distance from the center of the inner spherical surface in all positions of said spherical member, an electromagnetic coil forming a flux symmetrical about a plane into the center to form the highest flux density in said plane with the flux converging through said center, a plunger floating in said mercury pool and having an inner passage means, said plunger floating in off-center position, electrodes mounted in said spherical member extending in said passage means to a center area for variation in conductive relation on actuation of said plunger by said coil.

5. A liquid mercury electrical relay operable over a wide range of positions of the relay to the vertical and comprising hollow means having an inner spherical-lyshaped surface forming an inner chamber for contaning liquid mercury supported by said surface, a pool of liquid mercury in said chamber supported by said spherically-shaped surface to provide a liquid mercury surface forming at one surface level a clear center space at the center of the spherically-shaped surface, an electrode mounted on said hollow means and having a conductive end extending into the center space, an electromagnetic coil fixed in relation to said spherically-shaped surface and forming a flux having the highest flux density in the plane through the center of said spherically-shaped surface, a plunger of magnetic material having interior walls retaining the plunger around the electrode and being spaced therefrom to provide free movement transversely and longitudinally relative to said electrode over the range of positions of the relay, said plunger being centered by said flux to vary the surface of said pool of mercury and thereby the conductive relationship of the conductive end of the said electrode and the liquid mercury over a wide range of positions of the relay.

References Cited by the Examiner UNITED STATES PATENTS 12/1934 Hatay 200-112 3/1950 Russell et al 2001 12 

1. AN ELECTRIC RELAY COMPRISING A POOL OF LIQUID MERCURY, MEANS FOR SUPPORTING SAID POOL WITH A SURFACE IN SUBSTANTIALLY CONSTANT RELATION WITH A GIVEN CENTER AREA IRRESPECTIVE OF THE POSITION OF THE RELAY, CONDUCTIVE MEANS IN SAID CENTER AREA FOR BRIDGING BY SAID MERCURY POOL TO PASS CURRENT THEREWITH, AN ELECTROMAGNETIC COIL FORMING A FLUX HAVING THE CENTER CONVERGENCE IN SAID CENTER AREA AND A MAGNETIC PLUNGER FLOATING IN SAID MERCURY POOL IN AN OFFSET POSITION ON DEENERGIZATION OF SAID COIL IRRESPECTIVE OF THE POSITION OF SAID RELAY AND ACTUATED BY THE COIL TO MOVE TO AN INTERMEDIATE POSITION VARYING THE SURFACE OF THE POOL WITH RESPECT TO SAID CONDUCTIVE MEANS. 